To get a sharp image of an object, the surface of the object needs to lie within the focus range of an imaging system. The distance to the focus range is determined by the optical configuration of an imaging system. The relative movement between the imaging system and the imaged object may cause the object surface to lie outside the focus range, and the optical configuration of the imaging system needs to be adjusted to retain the focus.
When scanning samples with a digital microscope scanner each field of view may need to be focused separately to keep sample surface within the focus range. Focusing takes time and increases the overall scanning time. There is, therefore, a need for a solution that reduces the time needed for focusing.